Recently, since the abrupt progress of high technology, especially the relative field of the manufacture of the micro-electronic technology further changes day by day, so the computer has already penetrated into each family and business and become a necessary and indispensable electronic product. Following the prevalence of multi-media of computers, more peripheral products are needed as devices for input and output. Since the continuous innovation for the optical semi-conductor technology, so the product technology of the relative peripheral equipment of computers such as optical scanners becomes more matured day by day, and the optical scanner is more and more popular as a necessary product in the computer's peripheral equipment.
Please refer to FIG. 1A, which is a structural illustration of an embodiment of typical flatbed-type optical scanner used in prior arts. Its main structure includes a document window glass 12 arranged on the upper side surface of the outer shell 11 of an optical scanner for supporting a document 16 to be scanned. Brought along by a driving device 13, an optical chassis 14 makes a linear motion along the extension direction of the guiding rod 15 in the hollow outer shell 11 and a scanning job is then executed on the document 16 that is supported on the document window glass 12.
Please refer to FIG. 1B, which is a structural illustration of the axial sleeve apparatus for optical chassis used in prior arts. Wherein, an end surface of the optical chassis 14 has an axle sleeve apparatus 17, which is formed integrally with the optical chassis 14 and is connected with the driving apparatus 13 that is a power source (not shown in the figure) bringing along a belt 131 with an appropriate gear ratio. The belt 131 is connected with the optical chassis 14. Therefore, when the driving apparatus 13 brings along the axle sleeve apparatus 17, it is possible to make the both optical chassis 14 and axle sleeve apparatus 17 move synchronously, and by the guidance of the guiding rod 15, the optical chassis 14 makes a linear displacement motion along the guiding rod 15 for executing a scanning job.
Since the aforementioned axle sleeve apparatus 17 for optical chassis used in prior arts and the optical chassis 14 are formed and manufactured integrally, so the optical chassis 14 is connected on the guiding rod 15. Therefore, when the optical chassis 14 or the axle sleeve apparatus 17 for optical chassis is slightly damaged and needs to be changed, one has to take apart the entire outer shell 11 from the optical chassis 1 and the optical chassis 14 is drawn along and separated from the guiding rod 15 to proceed with the exchange. After changing the optical chassis 14, it has to re-proceed the assembly. When different resolutions of scanning are needed, one also has to change the optical chassis 14 according to the aforementioned method, so it causes inconvenience for changing and assembling the optical scanner 1.